The present invention relates to a safety device that is easily assembled and requires less number of parts.
A conventional safety device for pneumatic nailers is shown in FIGS. 1 and 2 and generally includes a push rod 10 having a threaded end 101 which is threadedly connected with a threaded hole 121 in an adjusting member 12. The adjusting member 12 is rotatably mounted to a pivotal member 13 which has a threaded rod 133 which extends through a hole 111 of a connection plate 111 and is connected with a nut 16. The connection plate 11 is connected to the trigger of the pneumatic nailer and the push rod 10 is movably connected to a nose portion of the nailer so that the trigger cannot be pulled if the push rod 10 is not pushed backward to move the connection plate 11. The threaded rod 133 has two surfaces 134 (only one is shown) so that when connecting with the nut 16, a wrench is used to hold at the surfaces 134 to prevent the pivotal member 13 from rotating with the nut 16. This takes time and requires a wrench to complete the engagement. The adjusting member 12 has two grooves 122 and 123 which respectively receive two C-shaped clamps 14, 15 therein. Two legs of the clamp 14 extend through the groove 122 and contact the notches 131 in the pivotal member 13. Two legs of the clamp 15 extend through the groove 123 and contact the notches 132 in the pivotal member 13. By the two clamps 14, 15, the adjusting member 12 can be rotated on the pivotal member 13 and positioned relative to the pivotal member 13. The two clamps 14, 15 both are connected to the adjusting member 12 so that the adjusting member 12 needs to be machined to have many grooves and holes. In some situations, there are only two threads connection between the threaded end 101 and the threaded hole 121, the huge vibration when operating the pneumatic nailer could separate the push rod and the adjusting member 12.
In accordance with one aspect of the present invention, there is provided a safety device for pneumatic nailers and the device comprises a push rod having a connection end which has a threaded section and a distal section. An adjusting member has a threaded hole defined through a first end of the adjusting member so that the threaded section is connected therewith. A recess is defined a second end of the adjusting member so as to receive a first end of a pivotal member. A first groove is defined in an outside of the second end of the adjusting member and two apertures communicate with the first groove and are defined through the adjusting member. A threaded rod extends from a second end of the pivotal member and a second groove is defined in an outer periphery of the first end of the pivotal member. Two notches communicate with the second groove and are defined through the pivotal member. A clamp is received in the first groove and two legs of the clamp extend through the apertures and are engaged with the notches. A passage is defined through the pivotal member so that the distal section extends through the threaded hole and the passage. Two plain surfaces are defined in a root portion of the threaded rod. A connection plate has a hole which has two straight insides and the threaded rod extends through the hole. The two plain surfaces of the threaded rod are engaged with the two straight insides of the hole and a nut is engaged with the threaded rod.
The primary object of the present invention is to provide a safety device for a pneumatic nailer wherein the connection of the nut and the threaded rod of the pivotal member needs no additional wrench.
Another object of the present invention is to provide a safety device for a pneumatic nailer wherein the connection end of the push rod extends in the pivotal member so that the push rod is- prevented from being disengaged from the adjusting member.
The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention.